Seminar - Physics Department

Quantum Galilean Cannon as a Schrodinger Cat

Maxim Olshanii, University of Massachusetts Boston

Thursday, September 14, 2017: 11:30am

LGRT 1033

Category: Condensed Matter Seminar

Refreshments at 11:15am

In this presentation we show that a quantum few-body system with a properly tuned set of masses is capable of evolving from a disentangled state to a state where the heavy particles are entangled with the light ones. Here, we focus on the so-called Galilean Cannon: a one-dimensional sequence of N hard-core particles in a ratio 1 : 1/3 : 1/6 : 1/10 : ... : 2/N(N+1) interacting with a hard wall. In this system, nontrivial conservation laws associated with a reflection group of an N-dimensional regular tetrahedron protect the evolution from both classical stochastization and quantum diffraction. In one of the examples, the Renyi entropy increases from zero in the beginning of the evolution to almost ln(2) in the end. We consider specie-alternating mutually repulsive bosonic soliton trains as an empirical realization of the scheme. We finally suggest a concrete way to exploit the heavy-light entanglement by proposing a quantum atomic sensor containing N_{atoms} atoms whose sensitivity is sqrt{N} higher than the one for a one-atom sensor with signal-to-noise reduced after N_{atoms} repetitions. Another attractive feature of this device is that it circumvents completely the usual difficulty in realizing beam-splitting of massive objects: in our scheme, the beamsplitter acts only on a single light particle, who is subsequently entangled with the heavy via robust processes only. In collaboration with Thibault Scoquart, Dmitry Yampolsky, Vanja Dunjko, and Steven Glenn Jackson. Supported by the NSF, ONR, SIRTEC and US-Israel Binational Science Foundation. TS's was supported by the École Normale Supérieure.